Apparatus and process for comminuting fibers



Dec. 15, 1942. y R. KERN APPARATUS AND PROCESS FOR commnunue FIBERS Filed July 11, 1941 Eaaglf [fem W diiTORNEYS Patented Dec. 15, 1942 UNITED STATES PATENT OFFICE mm'rus AND raocss's ron coMmNUnNG rmans Rudolf Kern, Siegburg, Germany; vested intlle Alien Property Custodian Application July 11, 1941, Serial No. 402,001

In Germany October 23, 1939 9 Claims.

staple fiber from endless artificial fibers, all of which have however been,found'.unsatisfactory' because of the difiiculty of properly handling,

feeding, and cutting fibers andfilarrientsvofsuch.

extreme thinness in a continuous uninterrupted process. In view of these difiic'ulties even the properly spread material axially along the cylinder.

Further objects and advantages of this invention will be apparent from consideration of the specification as illustrated by the accom panying drawing of possible embodiments of the invention, in which .drawing:

Fig. 1 illustrates more or less schematically oneform of device for carrying out the invention;

- Fig. 2 is a perspective view of a cutting rotor provided-with spiral or helical cutting blades;

feeding of the filaments by means ofazpowerful I water stream has been proposed,*in--'which':case the water stream and the filamentsand' fibers carried thereby are intersected by rotating knife blades to sever said fibers into short lengths. Even this has been found unsatisfactory for various reasons including the difliculty that the knife blades become dull in a relatively short time.

Numerous other methods and machines have been proposed but in all cases certain disad vantages have resulted; the usual one being the quick dulling of the blades so that the work had to be interrupted during sharpening or changing of the knives. As artificial fiber spinning is a continuous process interruption in the cutting operation is particularly objectionable.

It is an object of the present invention to provide a machine and process which overcome the disadvantages and difiiculties experienced heretofore.

Another object is to provide a machine in Fig. 3. is a more or less schematic view of a 'mo'di-fied illustrative embodiment of the invention.

In the form shown in Fig. 1 the letter a indi-. cates a cylinder rotating in the direction indicated by the arrow, this cylinder being formed with an accurate peripheral 'surface of stoneare preferably helically arranged. The rotor c which the cutting knives co-act substantially tangentially with thesurface of a cylinder or the like which cylinder preferably rotates in the same direction asthe movement of the knives but preferably at a lower peripheral speed.

It is another object to provide such a machine in which the cylinder which cooperates with the rotating knives serves also to feed the material to be cut.

Another object is to make the cylinder of such material and to dispose it in such a way that the cylinder will act continuously to sharpen the knife blades.

Another object is to form the cutting rotor cooperating with said cylinder with helically arranged cutting edges so that the point of contact moves alonggradually from one end of the cylinder and rotor to the other, thus producing a shearing cut, providing point contact instead of line contact and serving to distribute imis driven in the direction indicated by the arrow at a speed considerably greater than that of the cylinder a It will be noted that the leading edges of the blades 0' move in a path tangential to the periphery ofcylinders a. The material to be cutis preferably fed between the cylinder a and roller b by means of an endless belt feeding table of standard construction shown.

It will be noted that the material to be out, if not in contact with the .cylinder a, will be struck by the rotating blades 0' and severed tially thereof so that the cutting edge is not I dulled by contact with the cylinder a. On the contrary, the blades 0' are automatically sharpened in that their outer faces may rub against the periphery of the cylinder a. This automatic sharpening will take place whether the cylinder a is made of stoneware or otherabrasive material or of hard metal.

Another desirable feature is that the contacts between the blades c and the periphery of cylindera are point'contacts to provide for continuous cutting action and the points of contact are spread over the entire surface of cylinder a so that'any wear of the cylinder will be distributed over its large surface and will therefore be substantially negligible.

The result has been that whereas with machines used heretofore it was necessary to change knives every few hours and thereby disturb the operation of the entire plant, machines made according to the present invention have been operated for many hundreds of hours without indications of any substantial dulling of the knives.

Since the arrangement consists entirely of rotating elements no surfaces are present upon which material accumulations may form, thus assuring the greatest possible continuity of operation with the minimum ofattention.

The feed rollers b, b, b". firmly grip' the material so that it cannot be drawn forward by the pull exerted thereon by the rotating knife blades. as with acid remaining from the preceding operation, the excess moisture is pressed out by the rollers b, b, b", and said moisture is caught in the pan 9 immediately below the roller a and flows away through the conduit h.

As will be'seen in Fig. 2, the knife baldes c are preferably so constructed that if and when necessary the inner surfaces of their leading edges may be re-ground by suitable grinding machines of well known type.

Fig. 3 illustrates a suitable modified embodiment of the invention. In this case, the device comprises only three rotating cylinders, the feeding and abutment cylinder a made of stoneware or very hard metal, the pressure roller b adjustably pressed against the roller a and the cutting rotor c. e represents an endless belt conveyor for transporting the cut staple fiber from the cutting point to the next operation.

The roller b is supported upon the pivoted arm d upon which may be provided a slidable weight d for adjusting the pressure of the roller 1; upon the cylinder a. It will be noted that the parts are so arranged that the cutting blades while they do not touch the rollers b, pass very If the material to be out is moistened near thereto so that any fibers which might.

adhere to roller b and tend to wrap thereupon are thrown back by the rotating knives to the cutting points.

The invention is not intended to be limited to l the two forms shown, which are to be understood as illustrative only and not as limiting, as various changes in construction and arrangement may be made. all coming within the scope of the claims which follow:

1. Apparatus for cutting endless fibers and the like comprising a rotor provided with knife edges and a cylinder for transporting the material to be cut arranged tangentially to said rotor, said rotor being rotated at higher peripheral speed than said cylinder.

2. Apparatus for cutting endless fibers and the like comprising a cylinder and at least one roller spring pressed against said cylinder for transporting fibers to be out which are introduced between said cylinder and said roller,and a rotor provided with knife edges and arranged tangentially to said cylinder.

3. Apparatus for cutting endless fibers and the like comprising a cylinder and at least one roller spring pressed against said cylinder for transporting fibers to be out which are introduced between said cylinder and said roller, and a rotor provided with knife edges and arranged tangentially to said cylinder, said knife edges being arranged helically.

4. Apparatus for cutting endless fibers and the like comprising a rotor provided with knife edges and an abutment cylinder arranged tangentially to said rotor, the cylinder being made of harder material than said knife edges whereby said knife edges are automatically sharpened while cutting said fibers due to contact with said cylinder.

5. Apparatus for cutting endless fibers and the like comprising a rotor provided with knife edges and a cylinder for transporting the material to be cut arranged tangentially to said rotor, said knife edges being arranged helically whereby the fibers are severed by a drawing out both pripherally and axially of the cylinderrthe cylinder being made of harder material than said knife edges whereby said knife edges are automatically sharpened while cutting said fibers due to contact. with said cylinder.

6. Apparatus for cutting endless fibers and the like comprising a cylinder and at least one roller pressed against said cylinder for transporting fibers to be out which are introduced between said cylinder and said roller, and a rotor provided with knife edges arranged tangentially to said cylinder and arranged substantially tangent to said roller. v

7. Apparatus for cutting endless fibers and the like comprising a cylinder and at least one roller pressed against said cylinder for transporting fibers to be out which are introduced between said cylinder andsaid roller, and a rotor provided with knife edges and arranged tangentially to said cylinder, said roller being supported upon a pivoted frame, a lever connected with said frame and a weight arranged upon said lever for slidable adjustment lengthwise of said lever.

8. Method for cutting endless fibers comprising the steps of passing the material to be cut between an abutment cylinder and a feed roller and thereafter while being held by said feed'roller passing the fiber between said cylinder and a cutting rotor arranged tangentially to said cylinder.

9. Method for cutting endless fibers compris ing the steps of passing the material to be out between an abutment cylinder of abrasive material and a feed roller and thereafter while being held by said feed roller passing the fiber between said cylinder and a cutting rotor ar ranged tangentially to said cylinder whereby said fibers are cut into lengths determined by the speed of rotation of said cylinder and of said cutting rotor and said cutting rotor is sharpened by engagement with said abrasive cylinder.

RUDOLF KERN. 

